Let-off mechanism for looms



Mar h '10, 1925.

E. F. BALDWIN LET-OFF MECHANISM FOR LOOMS Original Filed Dec. 12,

Patented Mar. 10, 1925.

UNITED STATES PATENT oFFIcE.

EARL F. BALDWIN, OF GARDNER, MASSACHUSETTS, ASSIGNOR' TO AMERICAN FIBRE CORPORATION, OF GARDNER, MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS.

LET-OFF MECHANISM FOR LOO'MS.

Original application filed December 12, 1921, Serial No. 521,624. Divided and this application filed November 25, 1922.

nism for Looms, of which the following is a specification.

This invention relates to looms particularly designed for weaving fiber such as strands formed from paper strips, this ap plication being a division of my application Serial No. 521,624 filed December 12, 1921, for looms and relating to the let-off mechanism by which the warp strands are permitted to feed to the weaving mechanism, this mechanism acting to separately tension each strand but allowing all to move as a unit during the shedding.

For a more complete understanding of this invention, together with further ob jects and advantageous details and combinations of parts, reference may be had to the accompanying drawings in which Figure 1 is a fragmentaryrear elevation of the upper portion of the loomshowing the subject matter of the invention.

Figure 2 is a section on line 2-2 of Figure 1.

In the machine more fully shown and described in the above mentioned parent application for patent, of which the present application is a division, shedding may be effected progressively between the sides and center of width of the fabric by properly timing opposlte ends of the harnesses and because of this action of the mechanism causing progressive shedding, the warp threads must be drawn through the tension mechanism at somewhat different times. For this reason means for applying tension individually to the warp strands has been provided. As shown in the drawings, between the end frames 1 and 2 is positioned a bar 220 of somewhat T-shape in cross section. Passing through the end frame mem bers 1 and 2 are bolts 221 and 222 which engage within suitable sockets in the ends of the bar 220 and serve to pivotally mount this bar. Seated on the upper face of the bar 220 is a bar 223 having a series of openings 224 therethrough, one for each strand fixing them in adjusted position.

Serial N0. 603,339.

of warp material and positioned back of each opening 224'is an eye 225 flared outwardly at its rear end through which the strands may be threaded. Within each recess or opening 224 is pivoted a tension lever 226, the inner end of which is urg'ed downwardly toward the bar 220 to engage on the strand 'by means of a spring 227 seated in a socket 228 thereabove and'the tension of which may be adjusted by means of a plug 229 threaded inthe upper end of this socket. By grasping the upper end of the upper faces of the frame portions 1 and.

2. The tension on these springs may be regulated by means of screw rods 233 threaded through the upper ends of the portions 231 and having lock nuts 234 thereon for The extent to which these arms 230 may be swung downwardly toward the upper faces of the frame portions 1 and 2 is adjust-ably fixed by means of rods 235 threaded through lugs 236 extending forwardly of the portions 231 and striking at their lower ends on the frames. Lock nuts 237 may be employed to fix these rods in adjusted posit-ion. As the tension elements 226 engage the strands above the pivot bolts 221 and 222 tension exerted on the strands forwardly through the harnesses (not shown) tends to rock the arms 231 downwardly as far as permitted by the stop rods 235. The springs 232, however, are designed to be much heavier than the tension springs 228 for the individual strands so that the bar will yield as far as permitted by the rods 235, only when all the strands are tensioned at a point not quite suflicient to permit them to feed through their individual tensioning devices. Tension applied to a few strands causes them to pay through their individual tension devices without moving the bar. This permits a yielding of the tensioning device as a whole thereon, Warp "strand guides carried by "said Q bar 'at'onesidel of said fulcrum, individual tensionideviceslfor each warpfistrand carri'e'd by saidbar and/means for j'o pp'osifng;..

sage ofa strandthrough each of said guides,

said"resisting means and springs being so to the tension caused by the shedding motion of the harness frames and permits each strand to pay out v as it is additionally -tensioned due to the progressive shedding action to effect a substantially uniform 'tension'on all the strands,- .Lthe. springs 12232 acting. as

master :springs for the-entire setiofr-warp strands.

Having thus described certain emhodiments of this invention it should be evident to those s'killed in the art that manychanges able tensionin'g devices for warp strands carried by said bar, and means for carrying said permitting a limited, yieldingfmove ment thereof in'th'e' direction of motion of saidstrands. I I

"2. In; a loom, a tension bar fulcrum'ed rocking ofrsaid bar aboutits fulcruin -due to pun exerted 'on' said strands.

3.111 a 100m, a tensionfloar"fulc'rumed at its ends thereon, Warp strand guides-car- Hri'edfby said bar. atj'one side "of said fulernm,

atension lever for eaehgui'de, a. spring;

, pressing each tension lever againstthelstrand in the corresponding guide .to oppose, drawing of the. said strand. therethrough and springs opposingthe rockingof said bar about its fulcrum due .to'lt'he .pu'll exerted on said strands.

4.1m a loom, a tensionqbar' fu'lcrumedat si nature.

. ter; springs for holdingvsaid bar :rocked to one limit of motion opposed to tl1e::pull exerted thereon by said strands, said springs being so adjusted that said master springs "yield only under thecombined pullof substantially "all said strands insufiicient to effect their assa e ast their tension levers pull on-lndlvidual strands causing them to fecting said master springs.

' '5. Ina loom having end frames, a tension move past their, tension levers Without af- "barfulcrumed at its ends on-said frames for limited 'rockingimotion relative thereto, arms extending from 'opp'oslte ends of sa1d bar and overlying saidframes, master-springs seated in "sockets in said arms and bearing against sai'df'ramesto tend to hold "said-barat one limit" of -lts frockmg,r-vvarp strand guides carried by said bariat one:sideof said fulcru1n,-means acting 'to 'IGSlSt, the :pas-

' suflicient-to cause them to 'overcome'thei'r' resisting means Without rocking'saidbar.

flln-testlmony whereof I have a fiix'ed my EARL" F. BALDWIN. 

